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head/lib/libc/sys/brk.c
Property | Old Value | New Value |
---|---|---|
svn:keywords | null | FreeBSD=%H \ No newline at end of property |
/*- | |||||
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD | |||||
* | |||||
* Copyright (c) 2018 Mark Johnston <markj@FreeBSD.org> | |||||
* | |||||
* Redistribution and use in source and binary forms, with or without | |||||
* modification, are permitted provided that the following conditions | |||||
* are met: | |||||
* 1. Redistributions of source code must retain the above copyright | |||||
* notice, this list of conditions and the following disclaimer. | |||||
* 2. Redistributions in binary form must reproduce the above copyright | |||||
* notice, this list of conditions and the following disclaimer in the | |||||
* documentation and/or other materials provided with the distribution. | |||||
* | |||||
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |||||
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |||||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |||||
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |||||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |||||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |||||
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |||||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |||||
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |||||
* SUCH DAMAGE. | |||||
*/ | |||||
#include <sys/cdefs.h> | |||||
__FBSDID("$FreeBSD$"); | |||||
#include <sys/types.h> | |||||
#include <sys/syscall.h> | |||||
#include <errno.h> | |||||
#include <stdint.h> | |||||
#include <stdlib.h> | |||||
void *__sys_break(char *nsize); | |||||
static uintptr_t curbrk, minbrk; | |||||
static int curbrk_initted; | |||||
static int | |||||
initbrk(void) | |||||
{ | |||||
void *newbrk; | |||||
if (!curbrk_initted) { | |||||
newbrk = __sys_break(NULL); | |||||
if (newbrk == (void *)-1) | |||||
return (-1); | |||||
curbrk = minbrk = (uintptr_t)newbrk; | |||||
curbrk_initted = 1; | |||||
} | |||||
return (0); | |||||
} | |||||
static void * | |||||
mvbrk(void *addr) | |||||
{ | |||||
uintptr_t oldbrk; | |||||
if ((uintptr_t)addr < minbrk) { | |||||
/* Emulate legacy error handling in the syscall. */ | |||||
errno = EINVAL; | |||||
return ((void *)-1); | |||||
} | |||||
if (__sys_break(addr) == (void *)-1) | |||||
return ((void *)-1); | |||||
oldbrk = curbrk; | |||||
curbrk = (uintptr_t)addr; | |||||
return ((void *)oldbrk); | |||||
} | |||||
int | |||||
brk(const void *addr) | |||||
{ | |||||
if (initbrk() == -1) | |||||
return (-1); | |||||
if ((uintptr_t)addr < minbrk) | |||||
addr = (void *)minbrk; | |||||
return (mvbrk(__DECONST(void *, addr)) == (void *)-1 ? -1 : 0); | |||||
} | |||||
int | |||||
_brk(const void *addr) | |||||
{ | |||||
if (initbrk() == -1) | |||||
return (-1); | |||||
return (mvbrk(__DECONST(void *, addr)) == (void *)-1 ? -1 : 0); | |||||
} | |||||
void * | |||||
sbrk(intptr_t incr) | |||||
{ | |||||
if (initbrk() == -1) | |||||
return ((void *)-1); | |||||
if ((incr > 0 && curbrk + incr < curbrk) || | |||||
(incr < 0 && curbrk + incr > curbrk)) { | |||||
/* Emulate legacy error handling in the syscall. */ | |||||
errno = EINVAL; | |||||
return ((void *)-1); | |||||
} | |||||
return (mvbrk((void *)(curbrk + incr))); | |||||
} |